/* bzflag
 * Copyright (c) 1993-2020 Tim Riker
 *
 * This package is free software;  you can redistribute it and/or
 * modify it under the terms of the license found in the file
 * named COPYING that should have accompanied this file.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

// ServerControl.cpp : Server shutdown and ban file control
//

#include "bzfsAPI.h"
#include "plugin_utils.h"
#include <fstream>
#include <sstream>
#include <sys/types.h>
#include <sys/stat.h>

using namespace std;

enum action { join, part };

class ServerControl : public bz_Plugin
{
public:
    virtual const char* Name ()
    {
        return "Server Control";
    }
    virtual void Init ( const char* config );

    virtual void Event( bz_EventData *eventData );
    int loadConfig( const char *cmdLine );
private:
    void countPlayers( action act, bz_PlayerJoinPartEventData_V1 *data );
    void checkShutdown( void );
    void checkBanChanges( void );
    void checkMasterBanChanges( void );
    void fileAccessTime(const std::string filename, time_t *mtime, bool *error);
    string banFilename;
    string masterBanFilename;
    string resetServerOnceFilename;
    string resetServerAlwaysFilename;
    string banReloadMessage;
    string masterBanReloadMessage;
    time_t banFileAccessTime;
    bool banFileErrorLogged;
    time_t masterBanFileAccessTime;
    bool masterBanErrorLogged;
    int numPlayers;
    int numObservers;
    bool serverActive;
    bool ignoreObservers;
    double lastTime;
};

BZ_PLUGIN(ServerControl)

void ServerControl::Init ( const char* cmdLine )
{
    if (loadConfig(cmdLine) < 0)
        return;

    Register(bz_ePlayerJoinEvent);
    Register(bz_ePlayerPartEvent);
    Register(bz_eTickEvent);
}

int ServerControl::loadConfig(const char *cmdLine)
{
    PluginConfig config = PluginConfig(cmdLine);
    string section = "ServerControl";

    if (config.errors) return -1;

    serverActive = false;
    countPlayers( join, NULL );

    lastTime = 0.0;

    /*
     * Set up options from the configuration file
     */
    banFilename = config.item(section, "BanFile");
    masterBanFilename = config.item(section, "MasterBanFile");
    resetServerOnceFilename = config.item(section, "ResetServerOnceFile");
    resetServerAlwaysFilename = config.item(section, "ResetServerAlwaysFile");
    banReloadMessage = config.item(section, "BanReloadMessage");
    masterBanReloadMessage = config.item(section, "MasterBanReloadMessage");
    ignoreObservers = (config.item(section, "IgnoreObservers") != "");

    /*
     * Report settings
     */
    // Ban file
    if (banFilename == "")
        bz_debugMessagef(1, "ServerControl - No banfile checks - no BanFile specified");
    else
        bz_debugMessagef(1, "ServerControl - Monitoring ban file: %s", banFilename.c_str());
    // Ban reload message
    if (banReloadMessage == "")
        bz_debugMessagef(1, "ServerControl - No BanReloadMessage notification");
    else
        bz_debugMessagef(1, "ServerControl - BanReloadMessage: %s", banReloadMessage.c_str());
    // Masterban file
    if (masterBanFilename == "")
        bz_debugMessagef(1, "ServerControl - No masterban file checks - no MasterbanFile specified");
    else
        bz_debugMessagef(1, "ServerControl - Monitoring master ban file: %s", masterBanFilename.c_str());
    // Master Ban reload message
    if (masterBanReloadMessage == "")
        bz_debugMessagef(1, "ServerControl - No MasterBanReloadMessage notification");
    else
        bz_debugMessagef(1, "ServerControl - MasterBanReloadMessage: %s", masterBanReloadMessage.c_str());
    // Reset Server Once file
    if (resetServerOnceFilename == "")
        bz_debugMessagef(1, "ServerControl - No ResetServerOnceFile specified");
    else
        bz_debugMessagef(1, "ServerControl - Using ResetServerOnceFile: %s", resetServerOnceFilename.c_str());
    // Reset Server Always file
    if (resetServerAlwaysFilename == "")
        bz_debugMessagef(1, "ServerControl - No ResetServerAlwaysFile specified");
    else
        bz_debugMessagef(1, "ServerControl - Using ResetServerAlwaysFile: %s", resetServerAlwaysFilename.c_str());

    // Ignore Observers
    if (ignoreObservers)
        bz_debugMessage(1, "ServerControl - Ignoring Observers for server restarts");
    else
        bz_debugMessage(1, "ServerControl - Server must be empty for server restarts");

    /* Set the initial ban file access times */
    masterBanErrorLogged = false;
    banFileErrorLogged = false;
    if (masterBanFilename != "")
        fileAccessTime(masterBanFilename, &masterBanFileAccessTime, &masterBanErrorLogged);
    if (banFilename != "")
        fileAccessTime(banFilename, &banFileAccessTime, &banFileErrorLogged);

    return 0;
}

void ServerControl::fileAccessTime(const std::string filename, time_t *mtime, bool *error)
{
    struct stat buf;

    if (stat(filename.c_str(), &buf) == 0)
    {
        *mtime = buf.st_mtime;
        *error = false;
    }
    else
    {
        *mtime = 0;
        if (!*error)
        {
            bz_debugMessagef(0, "ServerControl - Can't stat the banfile %s",
                             filename.c_str());
            *error = true;
        }
    }
}

void ServerControl::checkShutdown( void )
{
    // Check for server shutdown
    //
    // We shutdown the server in the following cases:
    //   The server has no players and
    //     the reset server once file exists OR
    //     the reset server always file exists and someone was on the server
    //
    if ((numPlayers <= 0) || (ignoreObservers && (numPlayers - numObservers) <= 0))   // No players
    {
        if (resetServerOnceFilename != "")
        {
            std::ifstream resetOnce( resetServerOnceFilename.c_str() );
            if (resetOnce)   // Reset server once exists
            {
                resetOnce.close();
                remove( resetServerOnceFilename.c_str() );
                bz_debugMessagef(2, "ServerControl - Reset Server Once - SHUTDOWN");
                bz_shutdown();
            }
            else if (resetServerAlwaysFilename != "" && serverActive)
            {
                // Server was active - some non-observer player connected
                std::ifstream resetAlways( resetServerAlwaysFilename.c_str() );
                if (resetAlways)   // Reset server always exists
                {
                    resetAlways.close();
                    bz_debugMessagef(2, "ServerControl - Reset Server Always - SHUTDOWN");
                    bz_shutdown();
                }
            }
        }
    }
}

void ServerControl::Event( bz_EventData *eventData )
{
    bz_PlayerJoinPartEventData_V1 *data = (bz_PlayerJoinPartEventData_V1 *) eventData;

    if (eventData)
    {
        switch (eventData->eventType)
        {
        case bz_eTickEvent:
        {
            double now = bz_getCurrentTime();
            if ((now - lastTime) < 3.0) return;
            lastTime = now;
            checkShutdown();
            if (banFilename != "" )
                checkBanChanges();
            if (masterBanFilename != "")
                checkMasterBanChanges();
            break;
        }
        case bz_ePlayerJoinEvent:
            if (data->record->team >= eRogueTeam &&
                    data->record->team <= eHunterTeam &&
                    data->record->callsign != "")
                serverActive = true;
            countPlayers( join, data );
            break;
        case bz_ePlayerPartEvent:
            countPlayers( part, data );
            checkShutdown();
            break;
        default :
            break;
        }
    }
}

void ServerControl::countPlayers(action act, bz_PlayerJoinPartEventData_V1 *data)
{
    bz_APIIntList *playerList = bz_newIntList();
    int numLines = 0;
    int numObs = 0;

    bz_getPlayerIndexList( playerList );

    for ( unsigned int i = 0; i < playerList->size(); i++ )
    {
        bz_BasePlayerRecord *player = bz_getPlayerByIndex( playerList->get(i));
        if (player)
        {
            if (act == join || (data && (player->playerID != data->playerID) &&
                                (player->callsign != "")))
            {
                if (player->callsign != "")
                {
                    if (player->team == eObservers)
                        numObs++;
                    numLines++;
                }
            }
            bz_freePlayerRecord( player );
        }
    }
    numPlayers = numLines;
    numObservers = numObs;
    bz_debugMessagef(3, "serverControl - %d total players, %d observers", numPlayers, numObservers);
    bz_deleteIntList(playerList);
}

void ServerControl::checkBanChanges( void )
{
    time_t mtime;
    fileAccessTime(banFilename, &mtime, &banFileErrorLogged);

    if (mtime != banFileAccessTime)
    {
        banFileAccessTime = mtime;
        bz_debugMessagef(1, "serverControl - ban file changed - reloading...");
        bz_reloadLocalBans();
        bz_sendTextMessage(BZ_SERVER, BZ_ALLUSERS, banReloadMessage.c_str());
    }
}

void ServerControl::checkMasterBanChanges( void )
{
    time_t mtime;
    fileAccessTime(masterBanFilename, &mtime, &masterBanErrorLogged);
    if (mtime != masterBanFileAccessTime)
    {
        masterBanFileAccessTime = mtime;
        bz_debugMessagef(1, "serverControl: master ban file changed - reloading...");
        bz_reloadMasterBans();
        bz_sendTextMessage(BZ_SERVER, BZ_ALLUSERS, masterBanReloadMessage.c_str());
    }
}

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